1. Field of the Invention
The present invention relates to a card connector unit for accommodating a small memory card or what is known as an SD card and connecting a group of external connection terminals provided on this card to an electronic circuit provided in an electronic device such as a personal computer (PC), and more particularly to a card connector unit compatible with cards extended in length to be adaptable to multiple functions.
2. Description of the Related Art
Cards that can be freely inserted or withdrawn from an electronic device such as a PC or an electronic camera and permits writing or reading of information (hereinafter known as SD cards) are already known according to the prior art. This kind of card is substantially rectangularly shaped, and at one end of one side are arrayed a plurality of external connection terminals. The electronic device to accommodate such SD cards is provided with a circuit board on which are mounted required electronic circuits and a card connector unit for connecting the group of external connection terminals mounted on the SD card to the electronic circuits.
Such a card connector unit is provided with a housing having an accommodating space into which the SD card is to be inserted through an inlet, a plurality of terminal pieces fixed to this housing and exposed in the accommodating space, and a discharging mechanism for discharging an accommodated SD card.
The housing is usually configured by combining a frame made of an insulating material and a cover made of a metallic material or an insulating material, and an SD card accommodating space is formed between the frame and the cover. Each terminal piece is provided with a contact exposed within the accommodating space to be able to come into contact with the connection terminals of an SD card and a soldering portion to be soldered onto an electronic circuit provided in an electronic apparatus such as a personal computer (PC). It is so designed that, when an SD card inserted into the accommodating space is placed in a prescribed position, the group of its external connection terminals come into contact with the contact of each terminal piece.
A discharging mechanism of a known configuration, for instance, comprises a slider capable of reciprocating in engagement with an SD card, coil springs elastically energizing this slider in the direction of discharging the card, and engaging pins guided along a heart-shaped cam groove. When the operator presses with fingers the SD card placed in a prescribed position, on the edge toward him or her (rear edge), this configuration, by causing the slider and the engaging pin to work in conjunction, enables the card to move together with the slider outward to the operator""s side to be readily discharged. Another known configuration is such that, by operating a member for discharging action to release the SD card engaged in a prescribed position, the card can be discharged.
Incidentally, in connection with a recently rising call for the usability of an SD card not only as a mere recording medium but also as a communication device by providing it with a transmitter/receiver circuit or the like, the emergence of a new type SD card extended in length but the same in terminal specification as the conventional SD card is expected. A well conceivable use of such a new type SD card is, for instance, to arrange an antenna circuit for short range radio communication toward the rear end of an SD card of an extended length, keep the SD card in only a shallowly inserted position in the connector unit only when this antenna circuit is to be used, and insert the SD card deep into the connector unit when the antenna is not to be used.
However, since the conventional card connector unit does not have a structure to accommodate such a long SD card, it may allow the SD card to be inserted to a prescribed extent and electrically connected, but, for instance when the antenna circuit is not to be used, it is impossible to insert the SD card deeply and keep it there. Thus, if a card connector unit for a conventional card is to be adapted to a longer-than-usual SD card, the SD card will have to kept substantially protruding outward from the inlet of the accommodating space of the housing, not only will the appearance be awkward but also it will result in serious inconvenience of use because the electronic apparatus such as a laptop PC will have to be carried with the SD card kept inserted in the connector unit.
The present invention has been attempted to obviate these disadvantages of the prior art, and to provide a more convenient card connector unit allowing selective placement of an SD card of an extended length in any of positions differing in insertion depth.
In order to achieve the object noted above, a card connector unit according to the invention has a configuration comprising a housing having an accommodating space into which a card provided with a group of external connection terminals (SD card) is inserted from a side of an inlet and permitting the card to be selectively placed within the accommodating space in a first accommodating position in which an insertion depth is smaller or a second accommodating position in which an insertion depth is greater; terminal sections fixed to the housing to be exposed in the accommodating space and being in contact with the group of external connection terminals at least when the card is in the first accommodating position; and a shifting mechanism for driving the card inserted in the accommodating space to be shifted at least from the second accommodating position to the first accommodating position.
Since a connector unit of such a configuration not only allows a shorter SD card to be inserted and placed in the first accommodating position but also a longer SD card to be placed either in the first accommodating position or the second accommodating position, if the longer SD card is placed in the first accommodating position, for instance an antenna circuit built into that SD card can be exposed to enable it to be used as a communication device. Or if the longer SD card is inserted deep into the second accommodating position, it can be used as a recording medium or stowed in a state convenient for carrying. If the longer SD card placed in the first accommodating position is pressed by the operator deeper inward with fingers, the SD card can be easily shifted to the second accommodating position, and the longer SD card placed in the second accommodating position can be shifted to the first accommodating position using the shifting mechanism. Thus the longer SD card can be easily shifted from one accommodating position to the other.
Further in the above-described configuration according to the invention, the shifting mechanism may be provided with sliding members capable of reciprocating along an inserting/discharging direction of the card while being kept engaged with the card, engaging pins shifting along a heart-shaped cam groove along with shifting of the sliding members, and energizing members for elastically energizing the sliding members in a discharging direction of the card. If it is so arranged that, when the card is placed in the second accommodating position, the engaging pins may be engaged with pin engaging portions of the heart-shaped cam groove to inhibit shifting of the sliding members and, by pressing the card deeper in the accommodating space in such a state and thereby disengaging the engaging pins from the pin engaging portions, the card can be shifted in the discharging direction from the second accommodating position via the sliding members, the operator can press the SD card placed in the first accommodating position further inward to a prescribed extent to engage the engaging pins with the pin engaging portions of the heart-shaped cam groove to bring to halt the SD card in the second accommodating position. Or the operator can press the SD card placed in the second accommodating position to disengage the engaging pins from the pin engaging portions to direct the SD card to the first accommodating position with the elastic force of the energizing members. Therefore the longer SD card can be easily shifted from one accommodating position to the other.
If, in addition to this configuration, there is provided a discharging mechanism capable of discharging the card placed in the first accommodating position, when the SD card placed in the second accommodating position is to be discharged, there will be no need to rely only on the elasticity of the energizing members of the shifting mechanism and, if the energizing members are coil springs, the extent of their extension and contraction can be restrained to elongate their service lives. Nor will there be the phenomenon of an increase in reaction force with the elongation of the insertion depth of the SD card, resulting in improved operating ease.
In this case, the configuration may as well be such that the discharging mechanism is provided with a first sliding member capable of reciprocating along the inserting/discharging direction of the SD card; an engaging arm rotatably pivoted on this first sliding member and permitting engagement with the fore edge of the SD card; a first engaging pin shifting along a prescribed guide groove along with the shifting of the first sliding member, and a first energizing member for elastically energizing the first sliding member in the card discharging direction; and there may be further provided a rotation regulator for regulating outward rotation of the engaging arm when an inserted position of the card has not reached the first accommodating position, and a rotation permitting section for permitting outward rotation of the engaging arm and setting aside the engaging arm on the way of shifting of the card from the first accommodating position to the second accommodating position. Then, as the engaging arm steps aside into the rotation permitting section at a stage where the SD card is inserted midway between the first accommodating position and the second accommodating position, there is no need to set back the first sliding member any further, and the SD card can be pressed further inward while moving back the sliding members of the sliding member to bring it to the second accommodating position. Therefore, if the first energizing member is a coil spring for instance, the extent of its extension and contraction can be restrained to elongate its service life.
Or the guide groove of the discharging mechanism may as well be provided with a return path for guiding the first engaging pin in a process of shifting the SD card from the second accommodating position to the first accommodating position, a return pin engaging portion capable of holding the SD card in the first accommodating position by engaging the first engaging pin having passed the return path, and a proceeding path extending inward from the return pin engaging portion to enable the SD card to shift from the first accommodating position to the second accommodating position. Then, by engaging the first engaging pin with the return pin engaging portion, the first sliding member can be inhibited from shifting and the SD card can be held in the first accommodating position. Then, if the SD card is pressed further inward from the first accommodating position, the first engaging pin will be disengaged from the return pin engaging portion and shift further inward on the proceeding path, or if, conversely, the SD card is pressed outward from the second accommodating position outward by the shifting mechanism, the first engaging pin will shift outward to be engaged with the return pin engaging portion. Therefore, without having to using a complex configuration, the SD card can be easily and smoothly shifted between the first accommodating position and the second accommodating position.
To add, where the SD card placed in the first accommodating position is to be discharged with an operating member, the guide groove may be provided with a discharging path for guiding the first engaging pin in a process of shifting the card outward from the first accommodating position and an operating member for discharging the card placed in the first accommodating position, and the first engaging pin can be shifted from the return pin engaging portion to the discharging path by manipulating the operating member to press in the first engaging pin. Then the discharging can be simplified and made reliable without requiring a complex configuration.